The Biological Computer Graphics Facility of Columbia University functions as an interactive system with the Adage display terminal (AGT-50) connected to the IBM 360/91 of the Columbia University Computer Center via the high speed (10 to the 6th power bits/sec) link. In addition, a DEC computer (PDP 11/45) and a DEC display terminal (GT-40) have been incorporated, creating an overall system in which each machine talks to every other. The GT-40 has been supplemented with a Vanguard projector and a Numonics Tablet to create a low-cost stand-alone tracing terminal for general use. The present system and programs written for it are heavily used for 3-D nerve tracing from serial section micrographs to record and analyze spatial relationships between nerve cells and nerve fibers in nervous systems of small animals. The system is also used for a variety of problems in molecular biology. These include: a) molecular model building, energy minimization, and fitting together of protein molecule and protein molecules with small molecule inhibitors and substrates; b) the automatic interpretation of electron density maps to provide atomic coordinates of proteins from such maps; c) extensive studies are being carried out on the molecular interactions involved in causing sickle cell hemoglobin molecules to aggregate into microtubules which cause red cells to distort and therefore, have a reduced life span. Work on the facility has already led to one publication with a proposed model of this aggregation. Further calculations as well as new experimental work which use the computer graphics system are proposed under this renewal. In addition, we propose to expand the capabilities of the facility so that service can be provided for more outside users. We also propose to carry out an extensive project to automate the nerve tracing activities, so as to reduce the time required in this operation and therefore, allow many new types of experiments to be carried out.